1. Field of the Invention
The present invention relates to a control system and method for an internal combustion engine.
2. Description of the Related Art
Japanese Patent Application Publication No. JP-A-2004-225650 discloses a device for estimating the amount of exhaust gas in an air-fuel mixture in a combustion chamber of an internal combustion engine. Based on the recognition that the amount of heat generated in the combustion chamber can be estimated based on the pressure in the combustion chamber, the device according to Japanese Patent Application Publication No. JP-A-2004-225650 estimates the amount of exhaust gas in the air-fuel mixture in the combustion chamber based on the amount of heat generated in the combustion chamber.
However, while Japanese Patent Application Publication No. JP-A-2004-225650 is based on the recognition that the amount of heat generated in the combustion chamber correlates with the pressure in the combustion chamber, and that the amount of exhaust gas in the air-fuel mixture in the combustion chamber correlates with the amount of heat generated in the combustion chamber, as described above, it is not based on the recognition that the amount of exhaust gas in the air-fuel mixture in the combustion chamber correlates with the pattern of combustion in the combustion chamber, and hence with the torque obtained from the combustion.